2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2-(3,4,5-trimethoxyphenyl)-1H-benzimidazole

HRID 321957Notes

Reaction equation

HRID 321957 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[CH3:9][O:10][C:11]1[CH:12]=[C:13]([CH:16]=[C:17]([O:21][CH3:22])[C:18]=1[O:19][CH3:20])[CH:14]=O.ClC1C(=O)C(C#N)=C(C#N)C(=O)C=1Cl.[OH-].[Na+]>C(#N)C>[CH3:22][O:21][C:17]1[CH:16]=[C:13]([C:14]2[NH:8][C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=3[N:7]=2)[CH:12]=[C:11]([O:10][CH3:9])[C:18]=1[O:19][CH3:20]

Participants

6

Reactant 4

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 68583,4,5-TrimethoxybenzaldehydeHCID 7243O-PhenylenediamineHCID 14798Sodium Hydroxide

Product 1

HCID 7555442-(3,4,5-trimethoxyphenyl)-1H-benzimidazoleYield 14%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of 1,2-phenylenediamine (30 mmole, 3.24 g) and 3,4,5-trimethoxybenzaldehyde (30 mmole, 5.89 g) in acetonitrile (75 ml) is added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) (30 mmole, 6.81 g), and the mixture is stirred 18 hours at room temperature. Sodium hydroxide (0.5M, 120 ml) is added, and the mixture is stirred over night at room temperature. The dark precipitate is filtered off and is digested with ethanol (30 ml) to give the title product as a brown solid (14%). (R1=hydrogen, R2=3,4,5-trimethoxyphenyl, n=0). 1H-NMR (DMSO, TMS, δ): 3.74 (s, 3H, OCH3), 3.91 (s, 6H, OCH3), 7.20 (m, 2H, ar), 7.54 (s, 2H, ar), 7.61 (m, 2H, ar).

Workup

  1. stirringthe mixture is stirred over night at room temperature
  2. filtrationThe dark precipitate is filtered off

Sources & evidence

ORD record
ord-4e9b71b734694578bfd967e54ac3a99b
Source dataset
uspto-grants-2001_04
Patent number
US06211177B1

Reaction notes

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